The general aim of this investigation is to determine some of the factors that influence axonal growth during regeneration. Particular emphasis is given to studies of goldfish optic axons, which show exceptionally vigorous regeneration, with the hope that these studies may provide clues to procedures for enhancing axonal outgrowth and thus promoting recovery from damage to the central system in mammals. Some of the topics under investigation are the mechanisms of axonal transport in normal and regenerating cells, changes in axonal transport of calcium during regeneration, interactions between growing axon tip and the nerve cell body and the action of Nerve Growth Factor on regenerating cells. Also, the reaction of mammalian retinal ganglion cells to axotomy will be compared to the reaction of the corresponding cells in goldfish. The methods to be used will include radioactive labeling, light microscopy, electron microscopy, and behavioral testing.